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PEEN (peen)
The
part of the head of a hammer opposite the flat striking surface
Common
clues: Pounding part; Hammer end; Ball-___ hammer; Hammerhead
part; Rounded hammer part; Claw alternative; Spherical hammer
part; Hammer type
Crossword
puzzle frequency:
4 times a year
News:
Father
hits gunman with hammer
Video:
Smash It
With a Hammer
A
ball-peen hammer
A
ball-peen hammer is a type of peening hammer used in
metalworking. It
is distinguished from "point-peen" and "chisel-peen"
hammers by having a hemispherical head. Though the process of
peening has become rarer in metal fabrication, the ball-peen
hammer remains useful for many tasks.
The
original function of the hammer was to "peen" riveted
or welded material so that it will exhibit the same elastic
behavior as the surrounding material. Specifically, striking the
metal imparts a stress at the point of impact which results in
strain-hardening of that area. Strain hardening raises the
elastic limit of a material into the plastic range without
affecting its ultimate strength. A strain-hardened material will
not deform under the same low stresses as a non-hardened
material. Ultimately, Most metals can be "worked" by
such methods that they lose all of their ductile characteristics
and become strong but brittle.
The
ball-peen hammer is also used to expand and shape the free end of
copper roves, light rivets and similar, "setting" the
rivet in place to complete the joint. Peening is also the method
by which steel drums are formed and tuned.
A
ball-peen hammer is also known as an engineer's hammer or a
machinist's hammer and may be graded by the weight of the head.
This
article is licensed under the GNU
Free Documentation License.
It uses material from the Wikipedia
article "Ball-peen hammer".
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